Add XFAIL regression test for keyword expansion with long keywords.
Add XFAIL regression test for keyword expansion with long keywords.

* subversion/tests/libsvn_subr/subst_translate-test.c
  (test_one_long_keyword): New helper.
  (test_svn_subst_long_keywords): New test.
  (test_funcs): Add new test.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1467221 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion